1.) Ensure you have set up your Email Settings in Admin -> Email Settings and Admin -> Inbound Email appropriately.
2.) Ensure you have the AOP scheduler active in Admin -> Schedulers.
3.) I would recommend you take a look at our documentation and read the AOP user guide. You will also need Joomla and the AOP Joomla component, which can be found here.
I think you seem to have mixed up the difference between Open Source and No-Cost-To-Acquire Software. AOP is released under the GPL Licence which means its ‘Open Source’ and gives you Freedom.